One of the biggest challenges facing Preventive Oncology today is the better definition of high risk individuals. An ever growing body of data is transmitted to the public concerning cancer causation. This bombardment of information, while broadening our understanding, serves us poorly if conveys the impression that everything is carcinogenic and that the risk is universal. Preventive Oncology must begin to send the message that it is the rare exposure that is absolutely carcinogenic. We cannot consider the exposure without equal consideration of the genetic background which it affects. The challenge, then, is to find ways of identifying the susceptible subset of the population. I believe that susceptibility will increasingly be identified by biochemical means and the scientists who will move to the forefront in this identification are biochemical epidemiologists. In this emerging field, it is necessary to equip researchers with both the discipline of epidemiology and the skill of laboratory science. This award would provide me with the perfect opportunity to move into that arena. The training program which I have proposed will increase my skills in all areas of molecular oncology. I have chosen the laboratories and courses to complement each other and fill in those areas most necessary to a well founded biochemical epidemiologist. I will continue to teach during the course of the award, and hope stimulate the thinking of future researchers in this field. I have outlined a research program, based on the relationship between body iron stores and cancer susceptibility, which promises to serve as the starting point for a larger, more diverse program of biological susceptibility. This award will allow me to complete the necessary training, continue teaching, and launch a program which, I feel, will likely prove to be of great value to Preventive Oncology.